The present invention relates to a tape printing device and a corresponding tape cassette.
Known tape printing apparatus of the type with which the present invention is generally concerned are disclosed in EP-A-322918 and EP-A-322919 (Brother Kogyo Kabushiki Kaisha) and EP-A-267890 (Varitronics). These tape printing apparatus each include a cassette receiving bay for receiving a cassette or tape holding case. In EP-A-267890, the tape holding case houses an ink ribbon and a substrate tape, the latter comprising an upper image receiving layer secured to a backing layer by an adhesive. In EP-A-322918 and EP-A-322919, the tape holding case houses an ink ribbon, a transparent image receiving tape and a double-sided adhesive tape which is secured at one of its adhesive coated sides to the image receiving tape after printing and which has a backing layer peelable from its other adhesive coated side. With both these apparatus, the image transfer medium (ink ribbon) and the image receiving tape (substrate) are in the same cassette.
Once an image is printed onto the tape, a user may wish to put the printed label onto an article to be labelled. Thus, it is necessary to remove the releasable backing layer from the label. For making this process easier, a number of proposals have been published.
EP-A-0526213 discloses a tape printer with a cutting and peeling mechanism, in which the tape is clamped between two cooperating, stepped surfaces. The mechanism is provided with a cutting blade, as well, such that during peeling, a length of tape is simultaneously cut off from its supply. One of these surfaces provides a slot, into which a plunger (=the other surfaces) protrudes when peeling is performed. A similar arrangement, wherein a stepped surface is located on both sides of a cutting blade is disclosed in EP-A-0567299.
EP-A-0634276 discloses a tape printer with a cutting and peeling mechanism, as well. The plunger moves the tape into a slot provided in a cassette wall, and during retracting the tape manually from the mechanism, the cut end of the tape slides along a wall of the slot, such that the two layers tend to separate and peeling occurs.
In the prior art, the plunger and the longitudinal axis of the tape are arranged to include an angle of 90xc2x0. Thus, peeling is performed by bending the tape over its entire width. Since a predetermined force is required for releasing the backing tape from the adhesive image receiving layer, and this force is proportional to the area in which peeling is performed, relatively high forces are required, which make the operation of the peeling device less user friendly.
The object of the present invention is thus to overcome at least a part of the disadvantages of the prior art.
According to the invention, there is provided a combination of a tape printing device and a tape cassette, wherein:
the tape printing device comprises a peel plunger,
the tape cassette comprises a housing in which a supply of tape is provided, and a peel slot arranged for accomodation of the peel plunger is defined within a side wall of the housing,
the tape comprises an adhesive covered image receiving layer and a backing layer, and a portion of the tape is located between the peel plunger and the peel slot,
and the peel plunger is arranged to move the tape into the peel slot,
characterized in that the longitudinal axis of the peel slot and the longitudinal axis of the tape enclose a non-perpendicular angle.
The invention thus addresses the problem of peeling of tape, ie. the separation of the image receiving layer and the releasable backing layer. The invention proposes to have a non-perpendicular angle between the longitudinal axis of the peel slot and the longitudinal axis of the tape (=feed direction). Since the slot and the plunger are arranged parallel, such that the plunger can move into the slot, the longitudinal axis of the active plunger surface and the feed direction of the tape enclose a non-rectangular angle, as well, which is the same as the angle between peel slot and feeding direction. The angle can be between 30xc2x0 and 60xc2x0, preferably 45xc2x0. Since the peeled area is reduced, the peeling result is improved. The required force is made smaller, or the peeling result at a certain, available force (and thus area) is improved.
A corresponding tape cassette is also provided, with the following features:
a housing in which a supply of tape comprising an adhesive covered image receiving layer and a backing layer is contained,
a peel slot arranged in a side wall of the housing for accomodating a peel plunger,
whereby a portion of the tape is located at the side wall adjacent the peel slot,
characterized in that the longitudinal axis of the peel slot and the longitudinal axis of the tape enclose a non-perpendicular angle.
Additional advantageous features are recited in the dependent claims.